New insights into eutrophication management:Importance of temperature and water residence time

作     者：Feng Zhao Xu Zhan Hai Xu Guangwei Zhu Wei Zou Mengyuan Zhu Lijuan Kang Yulong Guo Xingchen Zhao Zicong Wang Wei Tang Feng Zhao;Xu Zhan;Hai Xu;Guangwei Zhu;Wei Zou;Mengyuan Zhu;Lijuan Kang;Yulong Guo;Xingchen Zhao;Zicong Wang;Wei Tang

作者机构：State Key Laboratory of Lake and EnvironmentNanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing 210008China University of Chinese Academy of SciencesBeijing 100049China School of Environmental and Civil EngineeringJiangnan UniversityWuxi 214122China 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2022年第34卷第1期

页      面：229-239页

核心收录：

学科分类：0830[工学-环境科学与工程（可授工学、理学、农学学位）] 08[工学] 0815[工学-水利工程] 

基　　金：jointly supported by the National Natural Science Foundation of China(Nos.41830757 41573076 and 41671494)。 

主　　题：Eutrophication N_(2):Ar method Temperature N:P ratio Lake water residence time 

摘      要：Eutrophication and harmful cyanobacterial blooms threaten water resources all over the world.There is a great controversy about controlling only phosphorus or controlling both nitrogen and phosphorus in the management of lake eutrophication.The primary argument against the dual nutrients control of eutrophication is that nitrogen fixation can compensate the nitrogen deficits.Thus,it is of great necessary to study the factors that can significantly affect the nitrogen fixation.Due to the difference of climate and human influence,the water quality of different lakes(such as water temperature,N:P ratio and water residence time)is also quite different.Numerous studies have reported that the low N:P ratio can intensify the nitrogen fixation capacities.However,the effects of temperature and water residence time on the nitrogen fixation remain unclear.Thus,30 shallows freshwater lakes in the eastern plain of China were selected to measure dissolved N_(2) and Ar concentrations through N_(2):Ar method using a membrane inlet mass spectrometer to quantify the nitrogen fixation capacities and investigate whether the temperature and water residence time have a great impact on nitrogen fixation.The results have shown that the short lake water residence time can severely inhibit the nitrogen fixation capacities through inhibiting the growth of nitrogenfixing cyanobacteria,changing the N:P ratio and resuspending the solids from sediments.Similarly,lakes with low water temperature also have a low nitrogen fixation capacity,suggesting that controlling nitrogen in such lakes is feasible if the growth of cyanobacteria is limited by nitrogen.